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This is a great article on the basics of RAID. Outside of consumer grade RAID systems it's a bit out of date. There are some perceptible performance differences
by yardie 7y ago
This is a great article on the basics of RAID. Outside of consumer grade RAID systems it's a bit out of date. There are some perceptible performance differences between enterprise and consumer storage systems.
I manage a small (<100TB) storage system for our office. We have servers using RAID10 SSDs and we have other servers using RAID10 10k SAS HDDs. The read performance on the SATA SSDs is great but the writes are atrocious.
- theevilsharpie 7y ago> The read performance on the SATA SSDs is great but the writes are atrocious. If a 10K SAS HDD array is outperforming even a single SATA SSD, either your I/O access pattern is extremely sequential, or there's something wrong with how your storage is configured.
- yardie 7y agoOur environment is almost entirely virtualized, so yes, extremely sequential. Each host has 2 or more 10Gbps NICs. So starting, suspending, moving, snapshoting and cloning a VM shows the limits in both. Our SAN is 4 years old and has tiered storage (10k SAS mainline HDDs and high-write SAS SSDs). We use cheaper SSDs in some instances. But there is a performance difference of 15%-25% between SAS and SATA and that can't be ignored.